Revolver

There are two common types of revolvers available today.
The single-action revolver requires shooters to cock the
hammer by hand before each shot. The trigger on a single-action
revolver will not function until the gun is cocked.

The double-action revolver
can fire in one of two ways. The
shooter squeezes the trigger to cock
and release the hammer. This
cocks and fires the gun. The shooter
also can first cock the hammer and then
squeeze the trigger, just like with
a single-action
revolver.

Revolvers cannot be fired unless the trigger is squeezed.
Generally speaking, old revolvers do not have safeties. Therefore,
you must use extra care when handling older revolvers because
they can fire if they are dropped when loaded!